Westport District— continued. page Kumara, Westland .. .. .. 43 Ross United Company, Ross .. .. . • 43 Mont dOr Company, Ross .. .. ..44 Humphrey's Gully Company .. .. 44 Phcenix Company, Skipper's .. .. .. 45 Maori Point, Shotover .. .. .. 47 Antimony-mining. Antimony Company, Queen Charlotte Sound .. 48 Dressing-works .. .. .. 48 Smolting-works.. .. .. .. 49 Singling process .. .. .. 49 Doubling process .. .. .. 49 Frenching or refining process .. .. 50 Furnace for smelting crude ore .. .. .. 50 Copper-mining. Champion Company, Nelson .. .. ..51 Character of country .. .. .. 52 Smelting-works.. .. .. .. ..53 Cost of producing copper .. .. 53 Ores and their Formations. Ore-deposits .. .. .. .. 54 Shape of deposits .. .. .. 55 Deposition of ore in chambers .. .. 55 Connection of ore-bodies with quartzitc .. .. 55 Manner of deposition of ore .. .. .. 56 Gold-ore .. .. .. .. 56 Silver-ore .. .. .. .. 56 Copper-ore .. .. .. .. 57 Lead-ore .. .. .. .. 57 Zinc-ore .. .. .. .. 58 Antimony-ore .. .. .. .. 58 Arsenic-ore .. . * .. .. 58 Mercury-ore .. .. .. .. 58 Platinum-ore .. .. .. .. 58 Manganese-ore .. .. .. .. 58 Nickel-ore .. .. .. .. 58 Iron-ore .. .. .. .. 58 Carbon-ore .. .. .. .. 58 Lime-ore .. .. .. .. 59 Silica-ore .. .. .. .. 59 Treatment of Gold- and Silver ores. Railey's plant .. .. .. .. 60 Crushing ore .. .. .. .. 62 Roasting process .. .. .. 62 Chloridizing process .. .. .. 62 Sifting the ore .. .. .. .. 63 Amalgamation .. .. .. .. 63 Leaching or lixiviation process .. .. 63 Precipitation of Metals. Silver .. .. .. .. .. 65 Gold .. .. .. .. .. ..66 Calcium-sulphide, manner of making .. .. 66 Calcium-hyposulphide, manner of making .. 66 Production of chlorine .. .. .. 60 Assays of ore from Tui Creek and Waihi .. .. 06 Table showing assay-results by C. A. Luckhardt, Francisco .. .. .. .. 69 Climo and Bawdon Machine .. .. .. 70 Frue's Concentrator .. .. .. 71 Vulcan Smelting-works, Onehunga .. .. 71 Now Era Company, Te Aroha .. .. .. 72 Newbury-Vautin process of chlorination .. .. 76 Treatment of Gold- and Silver-ores in America. Amalgamating-mills .. .. .. 79 Relative amount of ore milled .. .. .. 79 Capacity of mills .. .. .. 79 Tenor of ore treated .. .. .. 79 Working results .. .. .. 79 Cost of treatment .. .. .. 80 Reducibility of various ores .. .. 80 Terms of custom-mills .. .. .. 80 Stamp-batteries. Wet and dry crushing .. .. .. 80 Screens .. .. .. .. 80 Order in which stamps fall .. .. 81 Pan-amalgamation. Plant .. .. .. .. .. ..81 Pans for working ore .. .. 81 Method of heating pans .. .. .. 82 Number of revolutions of pans per minute .. 82 Weight of charge .. .. .. 82 Temperature .. .. .. .. 82 Time of working a charge .. .. 82 Continuous amalgamation .. .. 82 Grinding .. .. .. .. 82

a—6.

Pan-amalgamation —continued. page Quantity of quicksilver added .. .. 83 Chemicals used in amalgamation .. .. 83 Use of iron in pans .. .. .. 83 Loss of quicksilver .. .. .. 84 Clean-up pans .. .. .. .. 84 Settlers .. .. .. .. ..84 Agitators .. .. .. .. 84 Tailings .. .. .. .. ..84 Weathering of concentrations .. .. 85 Percentage recovered from concentrations .. 85 Treatment of tailings from silver-ores .. .. 85 Slimes.. .. .. .. .. 85 Samples of ore .. .. .. .. 85 Battery-samples .. .. .. 85 Ore-assays .. .. .. .. 85 Roasting-furnaccs. Systems of furnaces .. .. .. 85 Dimensions of furnaces .. .. .. 86 Capacity of different furnaces .. .. 87 Methods of feeding ore into furnaces .. .. 87 Methods of convoying ore to furnaces .. .. 87 Manipulation in roasting .. .. .. 87 Temperature maintained .. .. 87 Tenor of ore to be roasted .. .. 87 Duration of roasting process .. .. 88 Oxidizing roasting .. .. .. 88 Percentage of salt used .. .. .. 88 Sulphur-contents .. .. .. 88 Percentage of silver chloridized .. .. 88 Labour .. .. .. .. ..88 Fuel .. .. .. .. .. ..88 Power .. .. .. .. .. 88 Dust-chambers and flues .. .. 88 Amount of flue-dust caught .. .. 88 Loss of flue-dust .. .. .. 80 Different kinds of furnaces compared with each other .. .. .. .. ..89 Hydraulic Sluicing. General description .. .. .. 90 Yield of gold in gravel from important hydraulicmining claims in California .. .. 91 Results of working some of the hydraulic-mining claims in California .. .. .. 92 Length and grade of somo of the principal tunnel tail-races in California .. .. .. 93 Length, cost, and grades of important tunnel tailraces in Nevada .. .. .. .. 93 Details of work done in North Bloomfield Company's Claim, Nevada .. .. .. 93 Blasting Gravel-banks. Dardanelles Mine Blast .. .. .. .. ■ 94 Tail-races and Sluices. Grade .. .. .. .. .. .. 94 General efficient grade .. .. .. 94 Size of sluices .. .. .. .. 94 Construction of sluices .. .. .. 95 Blocks .. .. .. .. ..95 Laying down wooden blocks .. .. 95 Book-riffles .. .. .. ... 95 Undercurrents .. .. .. .. 95 Cleaning up .. .. .. 90 Charging the sluices .. .. .. 96 Loss of quicksilver .. .. .. 90 Table showing distribution of gold in sluices .. 97 Hydraulic pipes .. .. .. 98 Table of discharge of water from pipes .. .. 99 Construction of Pipes. Thickness of iron .. .. .. .. 100 Rivetting .. .. .. .. .. 101 Joints .. .. .. .. .. ..101 Air-valves and blow-offs .. .. .. .. 101 Coating of pipes .. .. .. .. 101 Cost of lrydraulic pipes .. .. .. .. 101 Table of weight of pipes .. .. .. 102 Table of price of pipes .. .. .. .. 102 Nozzles .. .. .. .. .. 103 Water-motors .. .. .. .. .. 103 Lifting boulders .. .. .. .. 10H Table of discharge of water from nozzles .. .. 104 Table of quantity of water and horse-power of Pelton Water-wheel, and also cost of same .. .. 105 Value of works constructed .. .. .. 100 Tstblo showing works in course of construction .. 107 Table showing works constructed.. .. .. 110 Table showing receipts and expenditure on waterraces .. .. .. .. .. 113

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